If you were to be consistent, you could use the figure for America's marginal tax rate listed in your second article, which is 37%. So apples to apples comparison would be that the US pays $22,000 in taxes at the highest marginal rate on 60k.
Keep in mind that the US also has state income tax, which can be upwards of an additional 15%.
Anyway, these figures are all kinds of wrong. You need to account for the progressive tax rate for each country, the state taxes you might be subject to, and the tax benefits / write offs that are available to you for your tax bracket.